Trichinella spiralis: Genomic Application to Control a Zoonotic Nematode

Makedonka      Mitreva; Douglas      P. Jasmer

Abstract

The nematode Trichinella spiralis and related species are zoonotic food-borne pathogens of humans. The muscle larval stage of this parasite establishes a chronic infection in skeletal muscle cells of humans who acquire trichinellosis. Muscle larvae also reside in skeletal muscles of animals, swine in particular, and other food animals, including game animals. These muscle larvae are the source of zoonotic transmission to humans. Once established, muscle larvae become less susceptible to anthelmintics that are effective against other stages of the parasite. Very little information exists to guide discovery of new drug targets and improved methods of eliminating muscle larvae established in muscle cells of humans or food animals. Here we discuss progress that has been made on sequencing the genome of T. spiralis. This informational resource should prove valuable for dissecting molecular characteristics of this parasite that warrant investigation as targets for chemotherapy. The availability of the T. spiralis genome has made possible the comparison of genomes from nematodes that span the evolutionary extremes of the phylum Nematoda. We describe a pan-phylum comparison of genomes that is underway. This comparative genomics approach is expected to identify molecular characteristics that are conserved among all nematodes, and hence applicable to nematode pathogens throughout the phylum, including species from the genus Trichinella. T. spiralis expression data for muscle larvae has been integrated with genome sequences to identify specific genes and proteins with relevance to control of this stage of the parasite. Examples are discussed in which genomic information may advance understanding of T. spiralis biology and new methods for treating infections by this parasite.

Keywords: Anthelmintics, comparative genomics, food-borne, genome, Trichinella spiralis, zoonotic, nematode, SEGMA, Rhabditina, C. elegans, C. briggsae, Meloidogyne incognita, M. hapla, ESTs, Markov clustering methods, MCL, Hidden Markov alignment Models, HMM, T. pseudospiralis, Trichuris and Trichinella, Gene Ontology, KEGG, AchR, D2L